Re: [ccp4bb] how to Collecting Data from Long Unit Cell Axes ?
Dear all, of course this may not always be possible, but let me suggest that in cases such as this, the original poster should consider to make her dataset (or at least 10 degrees at phi=0, and another 10 degrees at phi=90) available (by FTP or from a webserver, or even using a publicly accessible server such as Dropbox) to enable others to really try and index based on the raw data - it would educate all readers of the mailinglist when they learn about the success (or lack thereof) of processing such frames, and (hopefully) about the specific tricks that made it work. When given without sequence and protein name this should not leak too much information about your project, and solving this problem may be better than getting stuck! Best, Kay
[ccp4bb] diffraction of spherulites
Hey guys, When I collect data from these spherulites/crystals (grown in 0.1 M sodium acetate, 0.1 M MOPS pH 7.5, 12 % (w/v) PEG-8000, protein buffer: 100 mM NaCl, 50 mM HEPES pH 7.5): http://img695.imageshack.us/i/cryst.png/ I get this diffraction pattern: (it's not cryo protected, so there's some ice-rings also) http://img683.imageshack.us/i/diffv.jpg/ It can't be only ice-rings because those are usually starting at something like 3.8 A, whereas I already got one ring directly around the beam center and also one at about 20 A. Has anybody seen anything like that and tell me what it is? Stefan
Re: [ccp4bb] diffraction of spherulites
Hi Stefan, It looks like a powder diffraction-type image. http://en.wikipedia.org/wiki/Powder_diffraction You can imagine that your spherulites are made up of many small crystals in random orientations, a bit like a powder - this means that rather than getting discrete diffraction spots as you would hope to see for a single crystal, you see diffraction rings around the beam centre. HTH, Dave David C. Briggs PhD Father, Structural Biologist and Sceptic University of Manchester E-mail: david.c.bri...@manchester.ac.uk http://manchester.academia.edu/DavidBriggs (v.sensible) http://xtaldave.wordpress.com/ (sensible) http://xtaldave.posterous.com/ (less sensible) Twitter: @xtaldave Skype: DocDCB On 6 April 2011 09:32, Stefan Münnich wrote: > Hey guys, > > When I collect data from these spherulites/crystals (grown in 0.1 M sodium > acetate, 0.1 M MOPS pH 7.5, 12 % (w/v) PEG-8000, protein buffer: 100 mM > NaCl, 50 mM HEPES pH 7.5): > http://img695.imageshack.us/i/cryst.png/ > I get this diffraction pattern: (it's not cryo protected, so there's some > ice-rings also) > http://img683.imageshack.us/i/diffv.jpg/ > > It can't be only ice-rings because those are usually starting at something > like 3.8 A, whereas I already got one ring directly around the beam center > and also one at about 20 A. > Has anybody seen anything like that and tell me what it is? > > Stefan
Re: [ccp4bb] diffraction of spherulites
Hi Dave, thanks for your reply. Is there any chance of telling whether it is salt or protein from the diffraction image? Stefan On Apr 6, 2011, at 12:16 PM, David Briggs wrote: > Hi Stefan, > > It looks like a powder diffraction-type image. > > http://en.wikipedia.org/wiki/Powder_diffraction > > You can imagine that your spherulites are made up of many small > crystals in random orientations, a bit like a powder - this means that > rather than getting discrete diffraction spots as you would hope to > see for a single crystal, you see diffraction rings around the beam > centre. > > HTH, > > Dave > > > David C. Briggs PhD > Father, Structural Biologist and Sceptic > > University of Manchester E-mail: > david.c.bri...@manchester.ac.uk > > http://manchester.academia.edu/DavidBriggs (v.sensible) > http://xtaldave.wordpress.com/ (sensible) > http://xtaldave.posterous.com/ (less sensible) > Twitter: @xtaldave > Skype: DocDCB > > > > > On 6 April 2011 09:32, Stefan Münnich wrote: >> Hey guys, >> >> When I collect data from these spherulites/crystals (grown in 0.1 M sodium >> acetate, 0.1 M MOPS pH 7.5, 12 % (w/v) PEG-8000, protein buffer: 100 mM >> NaCl, 50 mM HEPES pH 7.5): >> http://img695.imageshack.us/i/cryst.png/ >> I get this diffraction pattern: (it's not cryo protected, so there's some >> ice-rings also) >> http://img683.imageshack.us/i/diffv.jpg/ >> >> It can't be only ice-rings because those are usually starting at something >> like 3.8 A, whereas I already got one ring directly around the beam center >> and also one at about 20 A. >> Has anybody seen anything like that and tell me what it is? >> >> Stefan
Re: [ccp4bb] diffraction of spherulites
Hi Stefan, IIRC, a ring at 20Å means that one of the cell edges is at least 20Å long - which might be considered unusually long for a salt crystal - but it's also on the short side for a protein cell edge - how big is your protein? If there are rings at lower resolution, then maybe these longer edges might be more indicative of protein spherulites, as opposed to salty ones. Can you wash some spherulites in mother liquor and run them on an SDS-PAGE gel? Dave David C. Briggs PhD Father, Structural Biologist and Sceptic University of Manchester E-mail: david.c.bri...@manchester.ac.uk http://manchester.academia.edu/DavidBriggs (v.sensible) http://xtaldave.wordpress.com/ (sensible) http://xtaldave.posterous.com/ (less sensible) Twitter: @xtaldave Skype: DocDCB On 6 April 2011 11:29, Stefan Münnich wrote: > Hi Dave, > > thanks for your reply. Is there any chance of telling whether it is salt or > protein from the diffraction image? > > Stefan > > > On Apr 6, 2011, at 12:16 PM, David Briggs wrote: > >> Hi Stefan, >> >> It looks like a powder diffraction-type image. >> >> http://en.wikipedia.org/wiki/Powder_diffraction >> >> You can imagine that your spherulites are made up of many small >> crystals in random orientations, a bit like a powder - this means that >> rather than getting discrete diffraction spots as you would hope to >> see for a single crystal, you see diffraction rings around the beam >> centre. >> >> HTH, >> >> Dave >> >> >> David C. Briggs PhD >> Father, Structural Biologist and Sceptic >> >> University of Manchester E-mail: >> david.c.bri...@manchester.ac.uk >> >> http://manchester.academia.edu/DavidBriggs (v.sensible) >> http://xtaldave.wordpress.com/ (sensible) >> http://xtaldave.posterous.com/ (less sensible) >> Twitter: @xtaldave >> Skype: DocDCB >> >> >> >> >> On 6 April 2011 09:32, Stefan Münnich wrote: >>> Hey guys, >>> >>> When I collect data from these spherulites/crystals (grown in 0.1 M sodium >>> acetate, 0.1 M MOPS pH 7.5, 12 % (w/v) PEG-8000, protein buffer: 100 mM >>> NaCl, 50 mM HEPES pH 7.5): >>> http://img695.imageshack.us/i/cryst.png/ >>> I get this diffraction pattern: (it's not cryo protected, so there's some >>> ice-rings also) >>> http://img683.imageshack.us/i/diffv.jpg/ >>> >>> It can't be only ice-rings because those are usually starting at something >>> like 3.8 A, whereas I already got one ring directly around the beam center >>> and also one at about 20 A. >>> Has anybody seen anything like that and tell me what it is? >>> >>> Stefan >
[ccp4bb] Twinning
Dear users, Is there a possibility that both non-merohedral twinning and partial hemihedral twinning occur in the same crystal? In one of the data in R3, sfcheck indicated twinning and thus upon using twinning option during refinement, refmac considered twinning operator of (k h -l). But the images also show some interpenetrating lattice spots which are characteristics of non-merohedral twinning. Probably one of the lattices have been more prominent and hence detected and processed by mosflm with an overall Rmerge of 8.2 at 2.35 Ang resolution. So is there such a possibility? Thanking you With Regards Kavya -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean.
Re: [ccp4bb] problem of conventions
Bernhard, > Well, "it" *IS* broke. As they say "it works for me", so either you're using a different set of programs from me, or you're using the same programs but in a different way. Perhaps you could be more specific as to which program(s) appear to be broken? If possible please post the logfile(s) on this forum, then someone might recognise the problem(s). Did you try reporting it to CCP4 (assuming of course we're talking about CCP4 programs)? You're the 2nd person in this thread to claim that the space-group handling for the alternate settings is broken, so it would be nice to get to the bottom of it! > If you are running some type of process, as you > implied in referring to LIMS, then there is a step in which you move from > the crystal system and point group to the actual space group. So, at that > point you identify P22121. The next clear step, automatically by software, > is to convert to P21212, and move on. That doesn't take an enormous amount > of code writing, and you have a clear trail on how you got there. I'm puzzled why I need a workaround for a bug that only you and possibly James have experienced: AFAIK no-one else has reported problems with this recently. Wouldn't it be make more sense to fix the bug(s)? - that way, everyone benefits and I don't need to do anything! Anyway, to respond to your suggestion: I've spent some time looking into this (so I hope you'll forgive the delay in replying!), and unfortunately it's not as simple as you think. I can see 3 main steps that would be required for a workaround: Step 1 (create new crystal form entry): First I would have to make a copy of the entry for the old crystal form in the PROTEINS table, giving it a new unique ID. Then I would perform the re-indexing/re-orientation operations on the reference & free-R MTZ files and the PDB file for the refined structure, and change the filename entries in the row of PROTEINS table just created to point to them. This row also contains the parameters for MR, rigid-body refinement, TLS and binding site definitions but these won't need to be changed. The user interface would need to be modified to give users the option of implementing this change, since I know some (most?) users who won't be happy to do it! One problem I foresee is confusing the users with a multiplicity of unit cells, since we already work with potentially 2 different cells per crystal: first the 'canonical' unit cell for the crystal form from the reference MTZ file header; then there's the unit cell for the isomorphous crystal as found by the indexing software. Users understand that the indexing program won't necessarily choose the reference cell, particularly in the situation you indicate below where 2 cell lengths are almost equal. Now you want me to add a 3rd possibly different unit cell, i.e. that after a second run of re-indexing to the 'standard setting'; the users won't understand the need for this. Next comes a tricky bit: for tracking purposes I would somehow need to make a link from the new crystal form to the old one, my guess is with a self-referencing foreign key. All the database applications for doing searches & reports would need to be modified to recognise this change. This doesn't look trivial to me! I would need to hand this task over to the database administrator & programmers, since I'm not involved with administration of the database. Getting a "clear trail" doesn't happen automatically, it has to be programmed! I anticipate some searching questions from all the users and the db admin, such as "why do we need to do this?", "what bad things will happen if we don't?" and "why haven't we seen these bad things happening before?". I'm hoping that you will be able to provide convincing answers to these questions - because I can't! Step 2 (re-index historical data): Then I would need to copy each entry for the historical datasets that were previously added to the database for the old crystal form to the new crystal form (of course it's actually _same_ crystal form, but we're fooling the LIMS into treating it as though it were a new one). This is so that we can continue to track the data using the new crystal form ID. All datasets for a given crystal form must be indexed in the same way since the LIMS interface allows you to mix & match PDB, MTZ & MAP files for the crystal form without the need to do superpositions (of course superpositions can be done if needed, but then you lose the symmetry info). These 'historical' datasets are all the ones generated in the process of getting and optimising the crystal form, i.e. from all the different constructs made (typically ~ 30 +- 20), the purifications and crystallisation trials, optimising the cryobuffer & DMSO concentration for soaking ligands, then the datasets used during the structure determination (MR/MAD/SAD etc). This may run to 100-150 datasets, but the actual number is immaterial since it's just as easy to write the database application for
[ccp4bb] FW: [ccp4bb] diffraction of spherulites
Stefan Could the low angle reflections be from lamellar liquid crystals of the PEG (or a mixed PEG/water phase). Seems like you have 1st,2nd and 4th order reflections with presumably the 2nd order about 20A. I think 40A lamellar spacing is characteristic of some PEG liquid crystals. Colin From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of Stefan Münnich Sent: 06 April 2011 09:33 To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] diffraction of spherulites Hey guys, When I collect data from these spherulites/crystals (grown in 0.1 M sodium acetate, 0.1 M MOPS pH 7.5, 12 % (w/v) PEG-8000, protein buffer: 100 mM NaCl, 50 mM HEPES pH 7.5): http://img695.imageshack.us/i/cryst.png/ I get this diffraction pattern: (it's not cryo protected, so there's some ice-rings also) http://img683.imageshack.us/i/diffv.jpg/ It can't be only ice-rings because those are usually starting at something like 3.8 A, whereas I already got one ring directly around the beam center and also one at about 20 A. Has anybody seen anything like that and tell me what it is? Stefan
Re: [ccp4bb] FW: [ccp4bb] diffraction of spherulites
It seems hard to imagine what there is anything in his solutions other than protein that would make spherulites, no? PEG 8000 at 12% seems pretty benign, unless the trays or screens have been sitting around for quite a while... JPK On Wed, Apr 6, 2011 at 12:04 PM, Colin Nave wrote: > > > Stefan > > Could the low angle reflections be from lamellar liquid crystals of the PEG > (or a mixed PEG/water phase). Seems like you have 1st,2nd and 4th order > reflections with presumably the 2nd order about 20A. > > I think 40A lamellar spacing is characteristic of some PEG liquid crystals. > > Colin > > > > > > From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of Stefan > Münnich > Sent: 06 April 2011 09:33 > To: CCP4BB@JISCMAIL.AC.UK > Subject: [ccp4bb] diffraction of spherulites > > > > Hey guys, > > > > > > When I collect data from these spherulites/crystals (grown in 0.1 M sodium > acetate, 0.1 M MOPS pH 7.5, 12 % (w/v) PEG-8000, protein buffer: 100 mM > NaCl, 50 mM HEPES pH 7.5): > > > > http://img695.imageshack.us/i/cryst.png/ > > > > I get this diffraction pattern: (it's not cryo protected, so there's some > ice-rings also) > > > > http://img683.imageshack.us/i/diffv.jpg/ > > > > It can't be only ice-rings because those are usually starting at something > like 3.8 A, whereas I already got one ring directly around the beam center > and also one at about 20 A. > > > > Has anybody seen anything like that and tell me what it is? > > > > > > Stefan -- *** Jacob Pearson Keller Northwestern University Medical Scientist Training Program cel: 773.608.9185 email: j-kell...@northwestern.edu ***
Re: [ccp4bb] **Possible spam**Re: [ccp4bb] FW: [ccp4bb] diffraction of spherulites
First few reflections seem characteristic of lamellar (rather than 3D crystals). Might be something other than PEG but see Magda El Nokaly, Stig E. Friberg, David W. Larsen, Lyotropic liquid crystals from lecithin, water, and polyethylene glycol, Journal of Colloid and Interface Science, Volume 98, Issue 1, March 1984, Pages 274-276, ISSN 0021-9797, DOI: 10.1016/0021-9797(84)90507-1. (http://www.sciencedirect.com/science/article/B6WHR-4RKW3SB-19/2/795b52beefd22e48f1958c167d9f4d0a) Colin > -Original Message- > From: Jacob Keller [mailto:j-kell...@fsm.northwestern.edu] > Sent: 06 April 2011 18:16 > To: Nave, Colin (DLSLtd,RAL,DIA) > Cc: CCP4BB@jiscmail.ac.uk > Subject: **Possible spam**Re: [ccp4bb] FW: [ccp4bb] diffraction of > spherulites > > It seems hard to imagine what there is anything in his solutions other > than protein that would make spherulites, no? PEG 8000 at 12% seems > pretty benign, unless the trays or screens have been sitting around > for quite a while... > > JPK > > On Wed, Apr 6, 2011 at 12:04 PM, Colin Nave > wrote: > > > > > > Stefan > > > > Could the low angle reflections be from lamellar liquid crystals of > the PEG > > (or a mixed PEG/water phase). Seems like you have 1st,2nd and 4th > order > > reflections with presumably the 2nd order about 20A. > > > > I think 40A lamellar spacing is characteristic of some PEG liquid > crystals. > > > > Colin > > > > > > > > > > > > From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of > Stefan > > Münnich > > Sent: 06 April 2011 09:33 > > To: CCP4BB@JISCMAIL.AC.UK > > Subject: [ccp4bb] diffraction of spherulites > > > > > > > > Hey guys, > > > > > > > > > > > > When I collect data from these spherulites/crystals (grown in 0.1 M > sodium > > acetate, 0.1 M MOPS pH 7.5, 12 % (w/v) PEG-8000, protein buffer: 100 > mM > > NaCl, 50 mM HEPES pH 7.5): > > > > > > > > http://img695.imageshack.us/i/cryst.png/ > > > > > > > > I get this diffraction pattern: (it's not cryo protected, so there's > some > > ice-rings also) > > > > > > > > http://img683.imageshack.us/i/diffv.jpg/ > > > > > > > > It can't be only ice-rings because those are usually starting at > something > > like 3.8 A, whereas I already got one ring directly around the beam > center > > and also one at about 20 A. > > > > > > > > Has anybody seen anything like that and tell me what it is? > > > > > > > > > > > > Stefan > > > > -- > *** > Jacob Pearson Keller > Northwestern University > Medical Scientist Training Program > cel: 773.608.9185 > email: j-kell...@northwestern.edu > ***
[ccp4bb] Advanced motif searches of the PDB (was: disulfide bond question)
Hi all, The following question was posed on the CCP4 bulletin board earlier this week: I have a question related to protein structure, but not crystallography per se. Has anyone see a disulfide forming between the two cys of "CXC" in the middle of a loop, and create a sharp turn, where X is not a proline? I seems to me that geometrically this would be possible but I am not sure how stable it is, or how energetically unfavorable it might be. This is the kind of task that can be carried out quickly and easily with PDBeMotif - and here's how to do it: (1) Surf to PDBeMotif at http://pdbe.org/motif (2) Click on the "Search" tab (or the "Search" link) (3) Select the option to search "Protein sequence, pattern" by clicking on the corresponding icon on the left of the page (fifth icon down) (4) In the sequence box enter: CXC (5) Select the radio button to search using "Pattern match on observed PDB sequences" (6) Click on "Add it to the search criteria" If we were to carry out the current search, we would get all observed instances of Cys-X-Cys in the PDB. However, we want to specify that the two cysteines are covalently linked. This can be done as follows: (7) Select the option to search "Interactions" by clicking on the corresponding icon on the left of the page (sixth icon down) (8) In the panel, change the two drop-down menus labelled "Interacting residue" so that one says "1" and the other says "3" (from their default value "any"). Also set the "Bond type" drop-down to "Covalent bond". (9) Click on "Add it to the search criteria" Now we have specified that we want to find instances of Cys-X-Cys, where there is a covalent bond between the two Cys residues (residues 1 and 3 in the pattern CXC). (10) Before you hit the "Search" button, you can limit the search with the "Normalise hits by" drop-down. If you select "-" you will get all instances in the PDB; if you select "UniProt", only one entry per UniProt ID will be retrieved, etc. (11) Hit the "Search" button (12) If you searched for all instances in the PDB, PDBeMotif will return a list of 147 hits in 55 PDB entries. If you normalised by PDB header, you will get 18 hits in 18 entries. (13) To visualise (some of) the hits, mark the check boxes of the instances you're interested in. Then select a visualisation program at the bottom of the page by clicking on its icon (e.g., Jmol). All the selected hits will be superimposed and shown in the selected viewer. For a screendump see: http://www.ebi.ac.uk/~gerard/cxc-motif.jpg (Note: if you're an advanced user, you may one day want to edit and submit your queries in XML - click on "Get Query XML" for more information.) - If you have any questions or comments about PDBeMotif, please use the feedback button at the top of any PDBe web page. --Gerard --- Gerard J. Kleywegt, PDBe, EMBL-EBI, Hinxton, UK ger...@ebi.ac.uk . pdbe.org Secretary: Pauline Haslam pdbe_ad...@ebi.ac.uk
[ccp4bb] diffraction of spherulites
I should point out that the reference I gave is quite misleading as the samples studied contained lecithin Apologies Colin > -Original Message- > From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of > Colin Nave > Sent: 06 April 2011 18:33 > To: CCP4BB@JISCMAIL.AC.UK > Subject: Re: [ccp4bb] **Possible spam**Re: [ccp4bb] FW: [ccp4bb] > diffraction of spherulites > > First few reflections seem characteristic of lamellar (rather than 3D > crystals). Might be something other than PEG but see > > Magda El Nokaly, Stig E. Friberg, David W. Larsen, Lyotropic liquid > crystals from lecithin, water, and polyethylene glycol, Journal of > Colloid and Interface Science, Volume 98, Issue 1, March 1984, Pages > 274-276, ISSN 0021-9797, DOI: 10.1016/0021-9797(84)90507-1. > (http://www.sciencedirect.com/science/article/B6WHR-4RKW3SB- > 19/2/795b52beefd22e48f1958c167d9f4d0a) > > > Colin > > > -Original Message- > > From: Jacob Keller [mailto:j-kell...@fsm.northwestern.edu] > > Sent: 06 April 2011 18:16 > > To: Nave, Colin (DLSLtd,RAL,DIA) > > Cc: CCP4BB@jiscmail.ac.uk > > Subject: **Possible spam**Re: [ccp4bb] FW: [ccp4bb] diffraction of > > spherulites > > > > It seems hard to imagine what there is anything in his solutions > other > > than protein that would make spherulites, no? PEG 8000 at 12% seems > > pretty benign, unless the trays or screens have been sitting around > > for quite a while... > > > > JPK > > > > On Wed, Apr 6, 2011 at 12:04 PM, Colin Nave > > > wrote: > > > > > > > > > Stefan > > > > > > Could the low angle reflections be from lamellar liquid crystals of > > the PEG > > > (or a mixed PEG/water phase). Seems like you have 1st,2nd and 4th > > order > > > reflections with presumably the 2nd order about 20A. > > > > > > I think 40A lamellar spacing is characteristic of some PEG liquid > > crystals. > > > > > > Colin > > > > > > > > > > > > > > > > > > From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf > Of > > Stefan > > > Münnich > > > Sent: 06 April 2011 09:33 > > > To: CCP4BB@JISCMAIL.AC.UK > > > Subject: [ccp4bb] diffraction of spherulites > > > > > > > > > > > > Hey guys, > > > > > > > > > > > > > > > > > > When I collect data from these spherulites/crystals (grown in 0.1 M > > sodium > > > acetate, 0.1 M MOPS pH 7.5, 12 % (w/v) PEG-8000, protein buffer: > 100 > > mM > > > NaCl, 50 mM HEPES pH 7.5): > > > > > > > > > > > > http://img695.imageshack.us/i/cryst.png/ > > > > > > > > > > > > I get this diffraction pattern: (it's not cryo protected, so > there's > > some > > > ice-rings also) > > > > > > > > > > > > http://img683.imageshack.us/i/diffv.jpg/ > > > > > > > > > > > > It can't be only ice-rings because those are usually starting at > > something > > > like 3.8 A, whereas I already got one ring directly around the beam > > center > > > and also one at about 20 A. > > > > > > > > > > > > Has anybody seen anything like that and tell me what it is? > > > > > > > > > > > > > > > > > > Stefan > > > > > > > > -- > > *** > > Jacob Pearson Keller > > Northwestern University > > Medical Scientist Training Program > > cel: 773.608.9185 > > email: j-kell...@northwestern.edu > > ***
Re: [ccp4bb] diffraction of spherulites
Stefan A second go! Can you compare the spacings of some of the rings, including the ones showing partial alignment, with the ones in this picture. http://www.pnas.org/content/102/2/315/F2.large.jpg PNAS January 11, 2005 vol. 102 no. 2 315-320 Molecular basis for amyloid fibril formation and stability O. Sumner Makin , Edward Atkins , Pawel Sikorski , Jan Johansson , and Louise C. Serpell For a powder diffraction pattern from 3D crystals of a folded protein see for example http://www.aps.anl.gov/Science/Future/Workshops/Biological_Crystallography/Summaries/VonDreele.htm Colin From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of Stefan Münnich Sent: 06 April 2011 09:33 To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] diffraction of spherulites Hey guys, When I collect data from these spherulites/crystals (grown in 0.1 M sodium acetate, 0.1 M MOPS pH 7.5, 12 % (w/v) PEG-8000, protein buffer: 100 mM NaCl, 50 mM HEPES pH 7.5): http://img695.imageshack.us/i/cryst.png/ I get this diffraction pattern: (it's not cryo protected, so there's some ice-rings also) http://img683.imageshack.us/i/diffv.jpg/ It can't be only ice-rings because those are usually starting at something like 3.8 A, whereas I already got one ring directly around the beam center and also one at about 20 A. Has anybody seen anything like that and tell me what it is? Stefan
[ccp4bb] LECTURER/SENIOR LECTURER IN STRUCTURAL BIOLOGY
Hi all, I have been asked to pass on the following details for a position at the University of Sydney. Please address all correspondence to the University of Sydney as detailed below. Cheers, Aaron LECTURER/SENIOR LECTURER IN STRUCTURAL BIOLOGY SCHOOL OF MOLECULAR BIOSCIENCE REFERENCE NO. 4269/1210 · Opportunity to drive a research program and develop teaching with a focus on structural biology · Tenure track position with packaged salary: $140.5K p.a. The University of Sydney is Australia's first University with an outstanding global reputation for academic and research excellence, and employs over 7500 permanent staff supporting over 49,000 students. The School of Molecular Bioscience is devoted to research and teaching in the areas of microbiology, biochemistry, molecular biology and genetics, cell biology and human nutrition. It has a strong reputation in the area of physical biochemistry and has access to a comprehensive range of modern research and teaching facilities. We attract an outstanding cohort of undergraduate students as well as postgraduate research students to this vibrant and world class research environment. In order to maintain and enhance the School’s teaching and research capacity across the broad discipline of structural biology, applications are invited for an academic appointment in any area of structural biology to undertake research, lecturing and laboratory teaching at undergraduate, honours and postgraduate levels. This is a full-time continuing (tenure track) career opportunity that will allow you to develop independent research and to become a new research leader for the school. You will also contribute to teaching and administration as a member of the academic staff. You will be required to have a PhD (or equivalent), as well as substantial postdoctoral experience and expertise in structural biology. Your research program should be focused on answering biological questions using a range of experimental approaches, with an emphasis on the determination of macromolecular structures using X-ray diffraction techniques. You will have an ability to contribute to teaching in lecture, tutorial and laboratory settings at all levels combined with a demonstrated ability to undertake independent research. Success in attracting competitive research funding will be highly regarded. Advanced skills in research training and supervision at the undergraduate and postgraduate levels including the writing of research grant applications and research papers are highly desirable. You will also be expected to contribute to the School’s professional and community engagement activities. Remuneration package: up to $140.5K p.a. including leave loading and up to 17% superannuation. Some assistance towards relocation cost and visa sponsorship may be available for the successful appointee if required and level of appointment will be commensurate with experience and qualifications. All applications must be submitted via the University of Sydney careers website. Visit sydney.edu.au/positions and search by the reference number for more information and to apply. CLOSING DATE: 23 May 2011 (11:30PM Sydney time) The University is an Equal Opportunity employer committed to equity, diversity and social inclusion. Applications from equity target groups and women are encouraged as they are underrepresented in this field. Aaron Philip McGrath Research Officer | Structural Biology THE CENTENARY INSTITUTE T +61 (0)2 9565 6282 | F +61 (0)2 9565 6101 | E a.mcgr...@centenary.org.au Locked Bag No. 6 | Newtown NSW 2042 | Australia
